AD/DHC-8/97 - Control Column Torque Tube (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Safety Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AD/DHC-8/97 Control Column Torque Tube 7/2004

Applicability: DHC-8 Models 102, 103, 106, 201, 202, 301, 311, 314, and 315 aircraft, serial numbers 003 through 584.

Requirement: Install control column torque tube catchers by incorporating ModSum 8Q101338; in accordance with instructions provided in Bombardier Service Bulletin 8-27-90, dated 28 October 2003.

Note: Transport Canada AD CF-2004-08 refers.

Compliance: Within 5,000 flight hours after 8 July 2004, unless already accomplished.

This Airworthiness Directive becomes effective on 8 July 2004.

Background: The manufacturer has identified that a single shear failure in the control column torque tube, inboard of its self-aligning bearings, could result in each of the pilot's and co-pilot's control column being supported by only one self-aligning bearing. This condition could result in reduced controllability of the aircraft.